Why is Saturday stronger than Monday?

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?

Can you find out which number multiplied by itself will give the output as 12345678987654321?

I am not a bull but I have horns.
I am not an ass but I have a pack saddle.
Wherever I go, I leave silver behind me.

Who am I?

A man has a barrel filled with oil that weighs 100 pounds, and then he puts something into it. Now the barrel weighs less than 100 pounds. What did he put in the barrel?

I throw two dice simultaneously.

What is the probability of getting a sum as 9 of the two numbers shown?

What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?

All of the flowers I have are orchids except two. All of the flowers I have are hibiscuses except two. All of the flowers I have are roses except two.

Can you tell me how many flowers I have?

We have four gears with below features=> Both Gear A and D has 60 teeth=> Gear B has 40 teeth=> Gear C has 20 teeth=> Every two minutes, Gear B makes 25 full turns.What is the relative speed of Gear A and Gear B?

I am weightless, but you can see me. Put me in a bucket, and I'll make it lighter. What am I?